Louis pfingst



(No Model.)

L. PFINGST.

GAR SPRING.

No. 462,971. Patented Nov. 10,1891.

Louis PFINGST, on BOSTON, MASSACHUSETTS.

.can senme.

srnomzcnTron forming part of Letters fatent Ibl'o. 462,971, dated November. 10, 1391. J Application filed liinyZd, 1891. Serial No. 393,896- (No model.) i

all whom it may concern Be'it known that LLon s PFINGST, of Bos-v ton, in the county of Sufitolk,,State of Massachusetts, have invented certain new and useful Improvements in Oar-Springs, t which the following is .a description suff ciently full, elm, and exact to enable any person skilled in'the art orscien'ce to whichsaid invention appertains to make and use the same, referencebeing had to'theaccompanying draw-- ings, forming part of this specification, in

.which l Figure -l isan elevation of 'my improved car-spring; Fig. 2, a like view of the same, showing the. springpartially compressed; Fig.-

' '3, a cross-sectiontakenon 'line w 00 in Fig. 1,

and Fig. 4 a plan view of the rod from which the spring is wound. 2

Like lettersof reference indicate corresponding parts in the different figures of the drawings. g a I My invention relates especially to supporting-springs for railway-cars and similar vehicles,'the object being to produce a springwhich shall be correspondingly sensitive in "cushioning the vehicle asthe load varies thereon. 1 The nature and operation of' the improve- .ment will be readily understood by'all conversant with such matters from the. following explanation.

Therspring A is formed from a rod circular in cross-section and of two diameters, the

body portion d of the rod being, for example, seven-eighths of aninchin diameter and at a pointfdrawn or reduced to five-eighthsof an inch in diameter for the remaining half 9 of itslength. When coiled, the portion d forms the base of the spring,- and the portion g forms the top C thereof, Said spring is wound on a mandrel of equal diameter throughout, rendering the coil thus formedot equal interiordiametenthe exterior diame-, ter of the top 0 being "correspondingly less thanthat of the base B. As thus constructed the top ,0 is more readily com pressed than the base B, and when the vehicle-is-sustaining a light load acts to cushion such load, while the degree of compression on the base B thereunder is practically imperceptiblel As the load increases the coil on the top 0 closes, as shown in Fig. 2, forming solid bearing for the vehicle 'on the base B, which then begins 'to compress under such increased Weight.

By thus constructing the-spring'with its upper and lower sections, respectively, of equal interior diameter much better results are effected than when the coil is formed from a rod 'of-e ual taper throughout;

1 The 10 z fitudinalrooking or oscillation of thecar-body is by the use of my improvedl. spring greatlyreduced, as where aspringpf' this class constructed of a bar of equal diamelter throughout is employed the oscillation of such springs greatly increases such rocking,

whereas the force of the weight is received by the smaller or upper portion of my improved spring without" compressing the larger portion or base, and the oscillation of such-'re- .v

duced portion alone has any effect on the carbody. I

In springs constructedfrom a barta ere its entire lengthand wound .into ,acoil equal i'nteriordiameter the smallenend of the taper or top coil. of the spring receives the blowfrom any movement of the body of the vehicle and soon. crystallizes,-causing it to become greatly weakened and easily broken. In conically--wound springsxfrom a bar of equal diameter throughout the lower or broader coiljs eifected in like manner. These objections are overcome by my improved constructio'n, wherein such blow is received by and imparted equally throughout the length I of the top or upper portiou C of the spring,

the same effect being had on the-base of the spring when the body is'sufiiciently loaded to entirely -compress theup'per G. 7

Having thus explained my: invention, what I claim iS- A spring comprising a spirally-wound 'rod,

that portion ofthe rod forming the lower portion of the springbeing of one size through;- outand that. portion of the rod forming the upper portion of the spring being smaller and of one size throughout, the interior diameters of the spiraljcoils being uniform'throu-ghout the spring, and the exterior diameter of' the lower portion bein'gjlargerthan that of the upper portion. LOUIS 1?FINGS'l..-

,Witnesses:

y 0. lYLSHAW, -K. .Duit un. 

